Thread: 07 Grand Prix GXP limited-slip diff??

I've been searching all over the net because I remember reading that Pontiac installed LSD's in the FWD to help cope with the GXP V8's power. So far I can't find a single reference to limited-slip diff's in FWD Grand Prix's.
Am I smoking too much medical parsley or something? I understand that the trannys were essentially beefed up stock units, but I know almost nothing about the differentials.
Anybody got the info on this?
PS: I'm a longtime Pontiac fan and this is my first post.